In a letter believed to have been written by the vice director of the Pentagon’s Joint Staff, defence experts raised the prospect of war in the Korean peninsula as the only viable solution to ending the threat from Pyongyang.
The memo was written in response to a request from two Congress members asking for “expected casualty assessments in a conflict with North Korea”, the Washington Post reported.
It said the only way of definitely finding Kim’s weapons bases was by ground invasion.
Such an action would almost certainly inspire a catastrophic response from the dictator, who is known to also be harbouring a stockpile chemical and biological weapons.
However the letter also expressed a preference for US Secretary of State Rex Tillerson to continue his diplomatic route of applying sanctions and economic pressure on the rogue state in a bid to derail its weapons programme.
A statement was signed by 16 Congressmen accompanying the letter and also seen by the Post concludes that the assessment “underscores what we’ve known all along: There are no good military options for North Korea”.
President Donald Trump has threatened North Korea repeatedly with military action if the country ever attacked US soil.
The commander-in-chief touched down in Japan today, for the start of a 12-day trip to Asia where the Korean crisis is expected to dominate discussions.
He ramped up his rhetoric against Pyongyang leader Kim almost immediately, telling soldiers at the Yokota Air Base near Tokyo: “No dictator, no regime, no nation should ever underestimate American resolve.
“Every once in a while, in the past, they underestimated us. It was not pleasant for them, was it?”
North Korea responded to Trump’s arrival in Asia with a threat of their own, saying the US President will receive “merciless punishment” for his “foolish remarks”.
North Korea’s newspaper of the ruling Workers’ Party of Korea, the Rodong Sinmun, published a comment piece accusing Mr Trump of “seriously stimulating” North Korea with his words.
The paper said Mr Trump must heed assertions from other US experts that he must “halt the reckless blackmail and take hands off the Korean affairs”.